Multi-track longitudinal, metal-in-gap head

ABSTRACT

A multi-track longitudinal magnetic tape head capable of writing data to high-coercivity magnetic tapes is disclosed. The multi-track, longitudinal magnetic tape head according to the present invention comprises a plurality of write elements and read elements. The write elements comprise a write pole separated from a substrate by a write gap. The write poles each comprise a block of magnetic material, having a planar gap surface and a convex top surface. A high B s  composition is deposited on an etched portion of the magnetic material of each write pole at the gap surface. As a result, the gap surface comprises high B s  composition extending from the top convex surface to a point part way down the gap surface. A method for manufacturing this multi-track longitudinal tape head is also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to magnetic tape heads, and morespecifically to a multi-track longitudinal tape head having a uniquemetal-in-gap configuration to increase gap-field strength.

2. Related Art

Magnetic tape drives are commonplace in today's computer industry. Thesetape drives are used to store digital information onto magnetic tapesand to subsequently read the stored information. Two examples of amagnetic tape drive are the IBM 3480 tape drive available fromInternational Business Machines in Armonk, N.Y., and the StorageTek 4480tape drive available from Storage Technology Corporation in Louisville,Colo.

Magnetic tapes are typically available in two formats: the cassette andthe cartridge. The cassette tape is a two-reel mechanism that includes asupply reel and a take-up reel. Cassette tape drives thread the magnetictape along a transport path, past one or more magnetic transducer heads,and then transport the tape such that it travels along the transportpath. The tape is taken from the supply reel and wound onto the take-upreel.

For cartridge tapes, the take-up reel is external to the tape cartridgeand typically provided internal to the tape drive. When a cartridge isinserted into a tape drive, it is threaded along the transport path bythe tape drive and fastened to the take-up reel.

Writing data to and reading data from the magnetic tapes is accomplishedusing a tape head. For data operations, tape heads are typicallymulti-track heads capable of reading and writing several streams of data(one per track) simultaneously.

A typical tape head assembly for a digital magnetic tape drive comprisesan approximately horseshoe-shaped core made from a magnetic materialsuch as ferrite. A coil of wire wound around the core is used to inducea magnetic field within the core. The open end of the horseshoe formswhat is referred to as a gap. Often times, the tape head manufacturingprocess leaves a slot at the opposite end of the horseshoe. This slot isknown as a "back gap" and has a comparatively low magnetic reluctance tothe flux lines through the core.

For write operations, a time-varying electric current is sent throughthe coil. This current is referred to as "write current." This writecurrent produces a time-varying magnetic field in the core. If the corewas a complete circle (e.g., a toroid) the magnetic flux lines wouldtravel in a circle along the core. Because the core is not a completecircle but has a gap, the flux lines bridge this gap and create a "gapfield."

The magnetic tape is passed over the gap at a predetermined distancesuch that the magnetic surface of the tape passes through a fringingfield from the gap. As the write current changes, the field at the gapchanges in intensity and direction. These temporal variations in gapfield result in a spatial pattern of magnetization on the magnetic tape.Thus, electronic data signals can be converted to magnetic signals andthe data stored magnetically on the magnetic tape.

To improve the quality of recordings, the audio and video industrieshave begun using high coercivity tapes. These tapes have a high residualflux density, B_(r), and require a high coercive force, H_(c), to writedata to the tape. An example of such a tape is a metal-particle magnetictape on which metal magnetic powder is coated on a non-magneticsubstrate, wherein the metal powder forms a thin magnetic layer.

To write information to a high coercivity tape, such as a metal-particletape, the strength of the magnetic field at the write gap must besufficient to overcome the high coercivity of the tape. The gap fieldneeded is typically greater than that which can be generated usingconventional ferrite heads. With conventional ferrite heads, the gapfield strength is substantially proportional to the write current, butonly up to a threshold level where the magnetic material on either sideof the frontgap (the pole tip) saturates. After this saturation point isreached, increases in write current lead to little or no increase in thegap field strength. This phenomenon is known as "pole-tip saturation."

Conventional videotape heads have been developed for writing to highcoercivity tapes. These tape heads are manufactured by forming amagnetic alloy with a high saturation magnetic flux density B_(s), suchas Sendust, on a non-magnetic or magnetic core half. The presence of thehigh B_(s) material on either or both sides of the front gap allows thevideo tape head to write to high coercivity tapes while avoiding theproblem of pole tip saturation. The layer of Sendust is typically formedusing vapor deposition techniques such as sputtering. An example of sucha conventional tape head is illustrated in FIG. 1. The major portion ofthis head is formed of glass or a like non-magnetic material 102, 104and a magnetic film 106. Magnetic film 106 is of a thickness equal tothe track width formed therebetween. Magnetic film 106 is typically ahigh B_(s) alloy such as Sendust.

Conventional tape heads such as the one illustrated in FIG. 1, arecommonly used with audio and video tape recorders. This and additionaltape head configurations using different configurations of high B_(s)alloys are described in U.S. Pat. No. 4,755,899 to Kobayashi, et al.,which is incorporated herein by reference.

The use of high coercivity tapes has been primarily confined to theaudio and video industries. Currently, high coercivity tapes are alsobeing used by data storage systems with tape transports and tape headssimilar to those used in the video industry. High B_(s) alloys, such asSendust, do not appear to have been used in multi-track longitudinaltape heads used for data storage.

A conventional multi-track longitudinal tape head module 200 isillustrated in FIG. 2. Referring now to FIG. 2, an alternating patternof read and write tracks is formed by providing an alternating patternof write closure poles 202 (referred to as write poles 202) and readclosure poles 206 (referred to as read poles 206) opposite a block ofsubstrate material 208 and separated by a gap 204. A write coil ispresent on substrate material 208 opposite write pole 202. A readdevice, such as a magneto-resistive sensor, is present on substratematerial 208 opposite read pole 206. Write poles 202 and read poles 206are embedded in a non-magnetic glass matrix insulator 210. The glassinsulator 210 between write poles 202 and read poles 206 acts as a trackisolator. Material 212, provided for structural purposes, can be eithermagnetic or non-magnetic material.

For read and write operations in two tape directions, two such modules200 are provided adjacent to one another. An example of thisconventional bi-directional, read-write tape head is illustrated in FIG.1 of U.S. Pat. No. 5,065,483 to Zammit. U.S. Pat. No. 5,065,483 isincorporated herein by reference.

Another conventional design for a multi-track longitudinal tape head isexemplified by the IBM 3480 and StorageTek 4480 18-track non interleavedtape heads. In this design, a first module is provided which compriseswrite closure poles opposite a first substrate with write coils. Asecond module is provided which comprises a solid block of ferriteopposite a second substrate with magneto-resistive sensors. The firstand second modules are configured adjacent to one another to provide aunidirectional read-after-write tapehead.

The magnetic tape travels across a front face of the tape headperpendicular to gap 204 in the directions illustrated by arrow 242. Thetop face, the face across which the magnetic tape travels, is typicallyconvex. During read and write operations, the tape is usually separatedfrom the top face of the tape head by a thin layer of air.

Apparently, in conventional multi-track, longitudinal magnetic tapeheads, write poles 202, and substrate 208 are made entirely ofnickel-zinc-ferrite, or manganese-zinc-ferrite. As a result, the gapfield strength of these conventional heads is not sufficient to writedata to high coercivity tapes.

What is needed is a longitudinal multi-track tape head capable ofwriting data to high coercivity magnetic tapes without the problem ofpole-tip saturation.

SUMMARY OF THE INVENTION

A multi-track longitudinal magnetic tape head capable of writing tohigh-coercivity magnetic tapes is disclosed. The magnetic tape headprovides a layer of a high B_(s) composition at the write gap to raisethe pole-tip-saturation point. As a result, a stronger gap field can begenerated, thereby allowing the head to write to high-coercivity tapes.

A write element is formed by positioning a write pole close to asubstrate and opposite a write coil on the substrate. The write pole andthe substrate are separated by a narrow gap. This creates a magneticcircuit capable of writing data to a track on the magnetic tape inresponse to a write current. The surfaces of the write pole andsubstrate that form the boundaries of the gap are planar surfaces calledgap surfaces.

Part of the gap surface of at least the write pole is etched to remove athin layer of the magnetic material. A high B_(s) composition isdeposited in place of the thin layer of pole material that has beenremoved. This thin layer of high B_(s) composition extends down from thetop surface of the write pole.

A read element is also provided and comprises a read pole positionedclosely to an inductive read coil or a magneto-resistive sensor locatedon the substrate. The read pole and the substrate are positioned suchthat a narrow gap is formed between them. An alternating pattern of readelements and write elements is formed by positioning the read poles andwrite poles together, separated from each other by a non-magneticmaterial. The gap surface of the alternating pattern of poles isprocessed such that it is planar.

The high B_(s) composition is not formed on the read poles. If the highB_(s) composition was formed on the read poles and inductive coils areused as read sensors, the junction between the high B_(s) compositionand the magnetic read pole could act as a second read gap and introduceunwanted noise into the read signal. Therefore, high B_(s) compositionis not provided on the read poles to avoid this potential problem.

The alternating pattern of read and write poles are created such thatthey appear embedded in a matrix of non-magnetic insulator such asglass. The insulator partially surrounds the poles such that the topsurface is exposed. It is this top surface that interfaces with thetape.

An advantage of the present invention is that it is a multi-track tapehead that is capable of generating gap field strength necessary to writedata to high-coercivity tapes such as metal-particle tapes.

Another advantage of the invention is the unique configuration of highB_(s) composition. According to a preferred embodiment, high B_(s)composition is provided on only that portion of the gap face of thewrite pole that is nearest to the head-to-tape interface. High B_(s)composition need not be deposited elsewhere on the gap surface. Thislessens concerns about unwanted eddy currents.

Still another advantage of the invention is that high B_(s) compositionis not used in conjunction with the read poles. This avoids thepotential dual read-gap problem.

Yet another advantage of the invention is that the gap face of the tapehead closure piece, including the read poles, write poles, and the glasstrack isolators, are a planar surface. This ensures the integrity of thegap line is maintained when the bonded closure and substrate pieces areprocessed to form a contour surface.

Further features and advantages of the present invention, as well as thestructure and operation, of various embodiments of the presentinvention, are described in detail below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to theaccompanying drawings. In the drawings, like reference numbers indicateidentical or functionally similar elements. Additionally, the left-mostdigits of a reference number identifies the drawing in which thereference number first appears.

FIG. 1 is a diagram illustrating a conventional single-track videomagnetic tape head.

FIG. 2 is a diagram illustrating a conventional multi-track longitudinalmagnetic tape head module.

FIG. 3 is a diagram illustrating a multi-track longitudinal magnetictape head module having a high B_(s) composition provided at the writegap.

FIG. 4A-4D illustrate the various manufacturing phases of a closureportion of the multi-track, longitudinal tape head module of the presentinvention.

FIG. 5 is a diagram illustrating a second read gap formed when a highB_(s) composition is included in a read pole.

FIG. 6 is a cross-sectional end view of a write track of a multi-tracklongitudinal magnetic tape head module having a high B_(s) compositionat the write gap.

FIG. 7 illustrates a multi-track longitudinal magnetic tape head modulehaving a high B_(s) composition on both sides of the write gap.

FIG. 8 is a perspective diagram illustrating the closure portion of amulti-track longitudinal magnetic tape head module having a high B_(s)composition on the write poles.

FIG. 9 is a flow chart illustrating the manufacturing steps forproducing read and write poles in accordance with the invention.

FIG. 10 is a diagram illustrating a situation where the closure gap faceis not a single contiguous planar surface.

FIG. 11 is a diagram illustrating a bi-directional read/writemulti-track, longitudinal magnetic tape head according to animplementation of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a multi-track, longitudinal, magnetic tape headcapable of providing a gap field strong enough to write information tohigh coercivity magnetic tapes. The configuration disclosed hereinprovides a magnetic gap field that is stronger than that provided byconventional tape heads whose write poles are made entirely of ferrite.

FIG. 3 is a perspective diagram illustrating a multi-track longitudinalmetal-in-gap tape head module 300 according to the present invention. Aread element is formed by providing a read closure pole 306 (referred toas read pole 306) separated from a substrate 308 by a gap 304. Theportion of gap adjacent to read pole 306 will be referred to as read gap304A. Read poles 306 and substrate 308 are usually made of magneticmaterials such as nickel-zinc ferrite or manganese-zinc ferrite.

Opposite read pole 306 on substrate 308 is a magneto-resistive sensor.As the magnetic tape passes over read gap 304A, the magnetic field fromthe tape alters the read gap flux density. The changes in flux as thetape travels across the head are sensed by the magneto-resistive sensor.

A write element is formed by positioning a write closure pole 302(referred to as write pole 302) separated from substrate 308 by gap 304.The portion of gap 304 between write pole 302 and substrate 308 will bereferred to as write gap 304B. Write poles 302 are separated fromadjacent read poles 306 by non-magnetic glass 210.

Opposite write pole 302 on substrate 308 is a write coil. As a writecurrent is applied to the write coil, a magnetic field is induced insubstrate 308 and write pole 302. The gap field in write gap 304B variesas a function of write current applied. As the magnetic tape passes overwrite gap 304B, the gap field changes the magnetization of magneticparticles on the tape, thus writing data to the magnetic tape.

The use of magneto-resistive sensors and write coils is well known inthe art and is described in U.S. Pat. No. 5,065,483 to Zammit withreference to FIG. 4 of that patent document.

With conventional longitudinal, multi-track tape heads (See FIG. 2)comprising write poles 202 made entirely of ferrite, the gap fieldcannot be strengthened to a point sufficient to allow writing to highcoercivity tapes.

Write pole 302 according to the present invention includes a thin layerof high B_(s) composition 312 adjacent to write gap 304B. In oneembodiment high B_(s) composition 312 is a high B_(s) alloy. This thinlayer of high B_(s) composition 312 raises the saturation point of thewrite pole tip so that the gap field can be increased above the levelthat could otherwise be accomplished with conventional ferrite heads. Asa result, the write element can provide the gap field needed to write tohigh coercivity magnetic tapes. An example of a suitable material forhigh B_(s) composition 312 is Sendust. Sendust is anIron-Aluminum-Silicon alloy.

In a preferred embodiment, thickness, t, of high B_(s) composition 312is approximately 2 microns. A suitable range of thicknesses would be 1to 6 microns. Other thicknesses could be chosen depending on thematerials used and the tape coercivity.

In another configuration, high B_(s) composition 312 could be made as alaminate including layers of materials such as a high B_(s) alloy andnon-magnetic layers such as silicon nitride. An example of such amulti-layered structure is provided in U.S. Pat. No. 4,901,179 to Satomiet al. which is incorporated herein by reference.

In FIG. 8, the closure portion of multi-track longitudinal metal-in-gaptapehead module 300 is illustrated. Tapehead module 300 comprises writepoles 302 and read poles 306. FIGS. 4A through 4D illustrate thisclosure portion of module 300 in various phases of fabrication. Thefabrication steps are illustrated in FIG. 9. Referring to FIGS. 4A-4D, 8and 9, in a step 902, a wafer of ferrite or other magnetic material isgrooved to form a block of slotted magnetic material 402. In a step 904a piece of glass insulating material 404 is placed between slottedmagnetic material 402 and an unslotted block of material 212. Material212 can be a magnetic or a non-magnetic material.

In a step 906, the layers of material 402, 404, 212 are is placed in anoven and fired. The firing causes glass 404 to melt and fill the groovesof slotted magnetic material 402. When cooled, the two pieces ofmaterial 402, 212 are fused together by glass 404 to form a block 408.

In a step 908, block 408 is ground and polished to expose glass 404 inthe grooves of slotted magnetic material 402. The result is illustratedin FIG. 4C. Gap face 420 is now a contiguous planar surface comprisingalternating rows of ferrite and glass. Each column of ferrite willultimately become either read or write closure poles.

In a step 910, trenches 410 (FIG. 4D) are formed along each ferritecolumn that is to become write closure poles. These trenches are formedusing the conventional processing techniques that include the steps ofphotoresist application, masking, photoprocessing, and ion milling. FIG.4D illustrates a process where the completed closure portion module 300will have an alternating pattern of read and write poles.

In a step 912, high B_(s) composition 312 is deposited on the entiresurface 420 using, for example, sputtering techniques. The area over thetrenches 410 is masked using photoresist techniques. Surface 420 is ionmilled to remove the high B_(s) composition from the unmasked areas.

In a step 914, the wafer is flat-lapped to provide a contiguous planarsurface of ferrite, high B_(s) composition and glass. This surface willform gap face 802.

In a step 916, after the wafer is flat-lapped a thin layer of insulatingmaterial is deposited thereon to cover the entire closure module.

In a step 918, the wafer is sliced at the high B_(s) compositionjunction (illustrated by dashed lines 430) to create a closure modulecomprising an alternating pattern of read and write closure poles withhigh B_(s) composition on the write closure poles. Step 918 can beperformed before step 914 in an alternative embodiment.

In a step 920 the closure module is bonded to a substrate (with read andwrite coils thereon) then ground and lapped to provide a substantiallyconvex top surface. The module is positioned such that gap 304 is formedbetween the gap faces of both halves, thus forming the configurationillustrated in FIG. 3. In a preferred embodiment, gap 304 is 1.2 micronswide ±100 nanometers. Other widths and tolerances may be chosen. Thewidth of gap 304 is controlled by controlling the thickness of theread/write coils affixed to substrate 308, the thickness of insulatinglayers on top of the read and write coils and also by controlling thethickness of the insulation layer deposited in step 916.

The closure module is positioned such that read closure poles areadjacent to the magneto-resistive sensors on the substrate, and writeclosure poles are adjacent to the write coils on the substrate.

Processing the closure as described above with reference to FIG. 9allows gap face 802 to have a planar surface. Having a single contiguousplanar surface provides a distinct advantage over a non-planar surface.FIG. 10 illustrates a multi-track tape head module wherein the gap faceof the alternate pattern of poles is not a single contiguous planarsurface. This is because, in this case, the poles were not etched beforehigh B_(s) composition 312 was deposited. Referring to FIG. 10, in thisnon-planar configuration, the edges of the high B_(s) composition 312are likely to crumble and lose their structural integrity when the tapehead module is taken through the mechanical processes of grinding andlapping after the closure and substrate bonding takes place. This hasthe result of changing the width of the write track written onto themagnetic tape. Providing a single contiguous planar surface eliminatesthis problem.

A cross-sectional end view of one write track is illustrated in FIG. 6.As can be seen in FIG. 6, write pole 302 is positioned such that gap 304separates it from substrate 308. Write gap 304B is at the top surface622 (which is a convex surface) of the write track. Write gap 304Bprovides a magnetic field to magnetic tape 602 passing over write gap304B at top surface 622. In this manner, data is written to magnetictape 602.

According to one embodiment, high B_(s) composition 312 is provided ononly the write pole 302 half of each write track. This embodiment isillustrated in FIGS. 3 and 6. A second embodiment has high B_(s)composition 312 on both write pole 302 and substrate 308 for each writetrack. Although more costly to manufacture, this alternative embodimentoffers potentially more uniform gapfield for write operations. Anexample of this alternative embodiment is illustrated in FIG. 7.

According to the present invention, high B_(s) composition 312 is notprovided on read pole 306 or on substrate 308 opposite thereto. FIG. 5illustrates a case where high B_(s) composition 312 is deposited on readpole 306. Referring now to FIG. 5, the standard read gap 304A is formedbetween high B_(s) composition 312 and substrate 308. Also, a secondread gap 510 is created if the junction between high B_(s) composition312 and read pole 306 is "magnetically dead." The flux in read gap 304Achanges continually as a magnetic tape passes over the read element.These changes are monitored by the magneto-resistive sensor present inread gap 304A. However, if an inductive coil is used as the read sensor,the second gap 510 will introduce unwanted noise into the signal.

The magnetic tape head module according to the present invention can beimplemented to provide a bi-directional read/write capability. FIG. 11illustrates a bi-directional read/write multi-track, longitudinalmagnetic tape head 1100. Referring to FIG. 11, two magnetic tape headread/write modules 300 are positioned adjacent to one another and areseparated by a shield 1102. Shield 1102 is used to magnetically isolatethe two tape head modules 300 and is typically made of copper or asimilar material.

Write poles 302 and read poles 306 are positioned on tape head module300A, 300B such that a read pole 306 on tape head module 300A isadjacent to a write pole 302 on tape head module 300B. Similarly, writepole 302 on tape head module 300A is adjacent to a read pole 306 on tapehead module 300B. In this configuration, data can be written to amagnetic tape traveling in a direction indicated by arrow 1122 by writeelements on tape head module 300B. This same data can be immediatelyread from the magnetic tape using the adjacent read element on tape headmodule 300A. Likewise, for a magnetic tape moving in the directionindicated by arrow 1124, data is written by a write element of tape headmodule 300A and immediately read by a read element of tape head module300B. By immediately reading the data that has been written in thismanner, it can be immediately determined whether a write error hasoccurred.

In an alternative embodiment, a magnetic tape head could be implementedwith a single read/write module 300.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not limitation. Thus, the breadth and scope of thepresent invention should not be limited by any of the above-describedexemplary embodiments, but should be defined only in accordance with thefollowing claims and their equivalents.

What is claimed is:
 1. A multi-track, longitudinal magnetic tape headfor writing information to high-coercivity magnetic tapes, comprising:aplurality of write poles, each having a first gap surface and a topsurface, wherein said top surface is adjacent to said first gap surfaceand at an angle to said first gap surface; a substrate comprising ablock of magnetic material having a second gap surface; wherein saidwrite poles are positioned such that said first gap surface of each saidwrite pole is substantially parallel to said second gap surface of saidsubstrate, and said first and second gap surfaces are separated so as toform a write gap therebetween; a plurality of coils, wherein each coilis positioned in proximity to a corresponding one of said write polesand said substrate such that each coil produces a gap field across eachsaid write gap in response to a write current provided to said coil;insulating material interposed between said write poles; and a thinlayer of high B_(s) provided on each said write pole at said first gapsurface such that said gap surfaces of said plurality of write polesform a single contiguous planar surface.
 2. The tape head of claim 1,wherein said thin layer of high B_(s) material is 1 to 6 microns thick.3. The tape head of claim 1, wherein said thin layer of high B_(s)material is 2 microns thick.
 4. The tape head of claim 1, furthercomprising:a plurality of read poles adjacent to said write poles, eachread pole having a third gap surface and a top surface, wherein said topsurface is adjacent to said third gap surface and at an angle to saidthird gap surface and wherein said third gap surface is separated fromsaid substrate by a narrow read gap; and an insulating materialinterposed between said read poles and said write poles.
 5. The tapehead of claim 4, wherein said plurality of read and write poles form acontiguous pattern of read and write poles, said read and write polesare separated from each other by said insulating material, and saidcontiguous pattern is positioned parallel to said substrate andseparated from said substrate by said read and write gaps.
 6. The tapehead of claim 5, wherein said contiguous pattern of read and write polesand said substrate are partially embedded in an insulating material. 7.The tape head of claim 5, wherein said contiguous pattern of read andwrite poles is an alternating pattern of read and write poles.
 8. Thetape head of claim 1, further comprising a thin layer of high B_(s)material provided on said substrate, adjacent to each said write gap. 9.The tape head of claim 1, wherein said high B_(s) composition is amultilayered laminate comprising alternating layers of a high B_(s)alloy and insulating material.
 10. The tape head of claim 1, whereinsaid high B_(s) composition is a high B_(s) alloy.
 11. A magnetic tapedrive capable of writing to high-coercivity magnetic tapes, comprising amulti-track longitudinal magnetic tape head capable of writinginformation to high-coercivity magnetic tapes, the multi-tracklongitudinal magnetic tape head comprising:a plurality of write poles,each having a first gap surface and a top surface, wherein said topsurface is adjacent to said first gap surface and at an angle to saidfirst gap surface; a substrate comprising a block of magnetic materialhaving a second gap surface; wherein said write poles are positionedsuch that said first gap surface of each said write pole issubstantially parallel to said second gap surface of said substrate, andsaid first and second gap surfaces are separated so as to form a writegap therebetween; a plurality of coils, wherein each coil is positionedin proximity to a corresponding one of said write poles and saidsubstrate such that each coil produces a gap field across each saidwrite gap in response to a write current provided to said coil;insulating material interposed between said write poles; and a thinlayer of high B_(s) material provided on each said write pole at saidfirst gap surface such that said gap surfaces of said plurality of writepoles form a single contiguous planar surface.
 12. The magnetic tapedrive of claim 11, wherein said magnetic tape head further comprises:aplurality of read poles adjacent to said write poles, each read polehaving a third gap surface and a top surface, wherein said top surfaceis adjacent to said third gap surface and at an angle to said third gapsurface and wherein said third gap surface is separated from saidsubstrate by a narrow read gap; and an insulating material interposedbetween said read poles and said write poles.
 13. The magnetic tapedrive of claim 12, wherein said plurality of read and write poles form acontiguous pattern of read and write poles, said read and write polesare separated from each other by said insulating material, and saidcontiguous pattern is positioned parallel to said substrate andseparated from said substrate by said read and write gaps.
 14. Themagnetic tape drive of claim 13, wherein said contiguous pattern of readand write poles and said substrate are partially embedded in aninsulating material.
 15. The magnetic tape drive of claim 13, whereinsaid contiguous pattern of read and write poles is an alternatingpattern of read and write poles.
 16. The magnetic tape drive of claim11, wherein said high B_(s) composition is a multi-layered laminatecomprising alternating layers of a high B_(s) alloy and insulatingmaterials.
 17. The magnetic tape drive of claim 11, wherein said highB_(s) composition is a high B_(s) alloy.
 18. The magnetic tape drive ofclaim 11, wherein said magnetic tape head further comprises high B_(s)composition deposited on said substrate, adjacent to said write gap. 19.The magnetic tape drive of claim 11, wherein said thin layer of highB_(s) material is 1 to 6 microns thick.
 20. The magnetic tape drive ofclaim 11, wherein said thin layer of high B_(s) material is 2 micronsthick.